As the Holy War continues its inexorable southward march, it is itself conquered from within—by Anasürimbor Kellhus.

From the arid Plains of Mengedda to the humid banks of the River Sempis, the Men of the Tusk wage relentless war against the heathen Fanim. While the Lords of the Holy War plot and squabble, Kellhus patiently extends his dominion. The sorcerer Achamian and his lover, Esmenet, submit entirely, only to have their faith—and their love—tested in unimaginable ways. The warrior Cnaiür falls ever deeper into madness, convinced that Kellhus will betray their pact to murder Kellhus’s father. And the skin-spies of the Consult watch with growing trepidation.

After a harrowing trek through the desert, the Holy War assembles about the walls of ancient Caraskand. At long last, Caraskand will fall. But another prophet has arisen, one who walks in their very midst: the Warrior-Prophet. Brother turns against brother. In the Holy War's most desperate hour, every man, every woman, is forced to choose.